Kevlar fibre & liquid resin provides the ultimate strong long lasting fix. Formulated to permanently seal radiator leaks, inlet manifolds and engine block leaks, cracks, leaking welch plugs and leaking gaskets without costly mechanical repair. This unique microfibre technology seeks out and plugs small leaks and cracks that cause coolant loss, loss of pressure and overheating. The DuPont? Kevlar fibres mesh and plug the leak or crack which are then encased in a hardened liquid glass resin for the ultimate permanent water tight seal. Nulon Radiator & Engine Block Stop Leak can be safely used in cars, trucks, vans, utes, and light commercial vehicles. Safe for all plastic, aluminium and metal (copper / steel) radiators, heater cores, gaskets and welch plugs. Safe to use with all types and colour of glycol anti-freeze/anti-boil and water based coolants.
Kevlar fibre & liquid resin provides the ultimate strong long lasting fix. Formulated to permanently seal radiator leaks, inlet manifolds and engine block leaks, cracks, leaking welch plugs and leaking gaskets without costly mechanical repair. This unique microfibre technology seeks out and plugs small leaks and cracks that cause coolant loss, loss of pressure and overheating. The DuPont? Kevlar fibres mesh and plug the leak or crack which are then encased in a hardened liquid glass resin for the ultimate permanent water tight seal. Nulon Radiator & Engine Block Stop Leak can be safely used in cars, trucks, vans, utes, and light commercial vehicles. Safe for all plastic, aluminium and metal (copper / steel) radiators, heater cores, gaskets and welch plugs. Safe to use with all types and colour of glycol anti-freeze/anti-boil and water based coolants.
Nulon REBSL-500 Radiator & Engine Block Stop Leak 500ml
Kevlar fibre & liquid resin provides the ultimate strong long lasting fix. Formulated to permanently seal radiator leaks, inlet manifolds and engine block leaks, cracks, leaking welch plugs and leaking gaskets without costly mechanical repair. This unique microfibre technology seeks out and plugs small leaks and cracks that cause coolant loss, loss of pressure and overheating. The DuPont? Kevlar fibres mesh and plug the leak or crack which are then encased in a hardened liquid glass resin for the ultimate permanent water tight seal. Nulon Radiator & Engine Block Stop Leak can be safely used in cars, trucks, vans, utes, and light commercial vehicles. Safe for all plastic, aluminium and metal (copper / steel) radiators, heater cores, gaskets and welch plugs. Safe to use with all types and colour of glycol anti-freeze/anti-boil and water based coolants.
Kevlar fibre & liquid resin provides the ultimate strong long lasting fix. Formulated to permanently seal radiator leaks, inlet manifolds and engine block leaks, cracks, leaking welch plugs and leaking gaskets without costly mechanical repair. This unique microfibre technology seeks out and plugs small leaks and cracks that cause coolant loss, loss of pressure and overheating. The DuPont? Kevlar fibres mesh and plug the leak or crack which are then encased in a hardened liquid glass resin for the ultimate permanent water tight seal. Nulon Radiator & Engine Block Stop Leak can be safely used in cars, trucks, vans, utes, and light commercial vehicles. Safe for all plastic, aluminium and metal (copper / steel) radiators, heater cores, gaskets and welch plugs. Safe to use with all types and colour of glycol anti-freeze/anti-boil and water based coolants.
in 29 offers
The lowest price for Nulon REBSL-500 Radiator & Engine Block Stop Leak 500ml right now is $15.52 at Allied Auto Online, compared across 22 retailers.
The all-time low was $11.87 on 16 July 2025 — today's price is 31% above the lowest ever. It has been notably cheaper before — worth setting a price alert.
Prices last updated 1 Oct 2026.
Last updated at 01/10/2026 10:16:16
Nulon Radiator & Engine Block Stop Leak 500ml REBSL-500
Free 60-day returns
Nulon Radiator Engine Block Stop Leak 500ml REBSL-500
Delivery between 2–15 Oct $10.95
Nulon Radiator & Engine Block Stop Leak 500ml Rebsl-500
Delivery $5
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Nulon Radiator & Engine Block Stop Leak REBSL 500ml | 6 Month
Free delivery
Affiliate Disclosure: We may receive a small commission for purchases made through this link at no extra cost to you. This helps support our site. Thank you!
Nulon Radiator Engine Block Stop Leak - 500ml
Delivery $11.47
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Nulon Radiator Stop Leak 500ml - Rebsl-500 Car Service Workshop Tool
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Nulon Radiator Engine Block Stop Leak 500ml Rebsl-500 P0065548
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Nulon Radiator And Engine Block Stop Leak 500ml Rebsl-500
Free delivery
Affiliate Disclosure: We may receive a small commission for purchases made through this link at no extra cost to you. This helps support our site. Thank you!
Nulon Radiator Engine Block Stop Leak 500ml
Free delivery
Nulon Radiator & Engine Block Stop Leak - 500ml
Delivery between 7–15 Oct $8.73
originally posted on supercheapauto.com.au
Brilliant stuff. Have used Seal Tite for years but this is better in my opinion. Blew a head gasket on a Triton 4G54 and it was bad. Pressurising the radiator and blowing water out exhaust. It wouldn't even wind over in the end, number 4 cylinder was full of water, it just hydrauliced. I thought there was no way this would work but it did. Saved me pulling the head off and doing head gasket.
originally posted on supercheapauto.com.au
My 1996 VS Caprice 5.0ltr V8 had typical blown headgasket problem. Right at the front of the cylinder head where the thermostat housing is. Bad enough that it brought on the over temp alarm within 10mins of idling. Blow steam out the gap bubble away like crazy. Followed the instructions, after 10mins idling sure enough over temp alarm came on so did the thermo fans etc. 5 mins of sitting at a high temp I thought she was a definitely scrap. Then low and behold the bubbling stopped. Thermos cut out and it returned to a normal operating temperature. Sat there for another 10 minutes at 1/4 gauge. Will continue to monitor it and be sure that it stays fixed.
originally posted on supercheapauto.com.au
Was crossing the Nullarbor and developed a radiator leak. Added it to the cooling system. It worked… but it also filled all the tubes of my radiator and stopped coolant from circulating through. Car overheated. Had to drive at night time for 4 days at 70km/h on a 110 km/h highway to get home without the car overheating. This product should have much better warnings in place for the potential harm it can cause. In our case we are very lucky not to have been stranded on the Nullarbor altogether.
| Capacity | 0.500 |
Nulon Radiator & Engine Block Stop Leak 500ml REBSL-500
Free 60-day returns
Nulon Radiator Engine Block Stop Leak 500ml REBSL-500
Delivery between 2–15 Oct $10.95
Nulon Radiator & Engine Block Stop Leak 500ml Rebsl-500
Delivery $5
Affiliate Disclosure: We may receive a small commission for purchases made through this link at no extra cost to you. This helps support our site. Thank you!
Nulon Radiator & Engine Block Stop Leak REBSL 500ml | 6 Month
Free delivery
Affiliate Disclosure: We may receive a small commission for purchases made through this link at no extra cost to you. This helps support our site. Thank you!
Nulon Radiator Engine Block Stop Leak - 500ml
Delivery $11.47
Affiliate Disclosure: We may receive a small commission for purchases made through this link at no extra cost to you. This helps support our site. Thank you!
Brilliant stuff. Have used Seal Tite for years but this is better in my opinion. Blew a head gasket on a Triton 4G54 and it was bad. Pressurising the radiator and blowing water out exhaust. It wouldn't even wind over in the end, number 4 cylinder was full of water, it just hydrauliced. I thought there was no way this would work but it did. Saved me pulling the head off and doing head gasket.
My 1996 VS Caprice 5.0ltr V8 had typical blown headgasket problem. Right at the front of the cylinder head where the thermostat housing is. Bad enough that it brought on the over temp alarm within 10mins of idling. Blow steam out the gap bubble away like crazy. Followed the instructions, after 10mins idling sure enough over temp alarm came on so did the thermo fans etc. 5 mins of sitting at a high temp I thought she was a definitely scrap. Then low and behold the bubbling stopped. Thermos cut out and it returned to a normal operating temperature. Sat there for another 10 minutes at 1/4 gauge. Will continue to monitor it and be sure that it stays fixed.
Was crossing the Nullarbor and developed a radiator leak. Added it to the cooling system. It worked… but it also filled all the tubes of my radiator and stopped coolant from circulating through. Car overheated. Had to drive at night time for 4 days at 70km/h on a 110 km/h highway to get home without the car overheating. This product should have much better warnings in place for the potential harm it can cause. In our case we are very lucky not to have been stranded on the Nullarbor altogether.
Worked great on a ?cracked cylinder? (coolant leaking into cylinder betweens runs, plus smokey startup) on turbo diesel. Too easy to use, just add then idle for 15 min. Had previously used traditional glass treatment (the old drain & flush coolant etc) that only lasted a few weeks. This one has not lost any coolant in 3 weeks so far
This stuff works really well, and it's super easy to use - just pour it in, top up the radiator & overflow, put the cap back on and run the engine for 15 minutes. Done.My car had minor leaks from the welsh plugs and then developed a pretty sizable leak from behind the water pump, to the point where I had to limit how much I could drive in one trip. After treating my engine with this it hasn't leaked another drop. I highly recommend it.
2007 Holden Captiva had a fairly bad coolant leak at the pipe going into the cylinder head.Mechanic said it was corroded and difficult to fix because the part wasn't available for 4-6 weeks and would have to be pressed into the cylinder head. Maybe even need the cylinder head replaced.Bought Nulon Stop Leak, followed the instructions and blow me away. It worked. No more leak. Liquid Gold this stuff.
After reading the reviews I though I try it as my Holden Combo Van was loosing water in Cylinder 2 and overheating. After using this product the coolant was no longer disapiering, I stopped having engine check light regarding cylinder 2 misfiring and overheating stopped. Try it and if in doubt they have a money back guarantee. I was about to pull the head off to replace the gasket but thought I try this stuff and it really worked.
I had a steady leak from my tractor radiator. I liked the look of this product as you add it to the radiator and leave it in there with your coolant, so in my mind that meant it should keep on working to protect against future leaks. I followed the simple directions and the leak slowed down and stopped after 10 minutes of idling the engine. I've since had the tractor working hard for a couple of hours and engine temperature remained normal and no sign of any leak. This product should be re-named to liquid magic!
Had a bad leak from around thermostat and was losing 1 litre of coolant every hour of driving, put in this product and fixed in minutes, went on a 50km highway drive to ensure properly mixed in and all fine. very happy. Well done Nulon, its good when these these products work.
Radiator had a good size leak from stone damage. Poured in half a bottle. Stopped it faster than expected. Has held well.
| Capacity | 0.500 |
